To the Editor: Although somewhat belated, the interesting account of a case of renal medullary cystic disease in an adolescent deserves some comment (Amer J Dis Child 107:277, 1964). It is stated that this is the first case with "proved salt loss." Strauss1 has reviewed this syndrome in 17 patients. Seven of these were between the ages of 8 and 18 at the time of death ("adolescent" form of medullary cystic disease), and five of the seven were clearly "salt-wasters." Such cases have prodigious urinary sodium losses, and hyponatremia is a frequent occurrence. The urinary sodium concentration in Dr. Faigel's report does not conclusively establish the presence of sodium wasting. Such concentration conceivably could occur as part of the urea-loaded diuresis confronting the residual nephrons. The case of sodium wasting detailed by Strauss2 was of a more profound degree.
The presence of a refractory anemia with a hypoplastic